跪求大神帮看一下WinBUGS中的初值问题

歪歪公主

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收藏 2014-03-23

悬赏 10 个论坛币未解决

我在贝叶斯推断的突变点研究，为什么赋初值时出错，显示this chain contains uninitialized variables，代码如下（我第一次用这个软件，还不太会）：
model
      {
            for (i in 3:N)
                     {
                     y ~ dnorm (mu, tao[J])
                     mu <- alpha[J]+beta[J]*i+gamma*x1
                     J<-1+step(i-x.change1)+step(i-x.change2)
                     x1<-y[i-1]
                     }
            for(i in 1:N-2)
                     {
                     punif<-1/(N-2)
                     }
            for(j in 1:3)
            {
            alpha[j] ~ dnorm(0,0.001)
            beta[j] ~ dnorm(0,0.001)
            tao[j] ~ dgamma(1.001,0.001)
            }
            k[1]~dcat(punif[])
            k[2]~dcat(punif[])
            x.change1<-ranked(k[],1)+1
            x.change2<-ranked(k[],1)+1
            gamma ~ dnorm(0,0.001)
      }

list(N=56,y=c(3209.91,3075.50,2889.01,3008.79,3206.36,3220.19,3163.76,2987.03,3056.84,3053.39,2661.87,2541.40,2493.39,2636.22,2645.26,2942.52,2973.67,2845.88,2766.58,2872.01,2941.89,2995.94,2827.07,2708.68,2773.56,2592.50,2460.17,2401.14,2456.55,2248.84,2250.15,2365.99,2383.88,2356.65,2388.54,2282.52,2168.81,2114.29,2070.15,2100.09,2042.74,2124.66,2311.04,2380.36,2296.43,2211.80,2264.51,2119.15,2013.65,2073.82,2185.35,2186.71,2161.97,2163.38,2036.28,2091.49))

list(alpha=c(0,0,0),beta=c(0,0,0),tao(0,0,0)=(0.01,0.01,0.01),gamma=0,k=c(2,2))